// Copyright 2018 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_OBJECTS_FREE_SPACE_H_
#define V8_OBJECTS_FREE_SPACE_H_

#include "src/objects/heap-object.h"
#include "torque-generated/class-definitions-from-dsl.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

    // FreeSpace are fixed-size free memory blocks used by the heap and GC.
    // They look like heap objects (are heap object tagged and have a map) so that
    // the heap remains iterable.  They have a size and a next pointer.
    // The next pointer is the raw address of the next FreeSpace object (or NULL)
    // in the free list.
    class FreeSpace : public HeapObject {
    public:
        // [size]: size of the free space including the header.
        inline int size() const;
        inline void set_size(int value);

        inline int relaxed_read_size() const;
        inline void relaxed_write_size(int value);

        inline int Size();

        // Accessors for the next field.
        inline FreeSpace next();
        inline void set_next(FreeSpace next);

        inline static FreeSpace cast(HeapObject obj);
        inline static FreeSpace unchecked_cast(const Object obj);

        // Dispatched behavior.
        DECL_PRINTER(FreeSpace)
        DECL_VERIFIER(FreeSpace)

        DEFINE_FIELD_OFFSET_CONSTANTS(HeapObject::kHeaderSize,
            TORQUE_GENERATED_FREE_SPACE_FIELDS)

        OBJECT_CONSTRUCTORS(FreeSpace, HeapObject);
    };

} // namespace internal
} // namespace v8

#include "src/objects/object-macros-undef.h"

#endif // V8_OBJECTS_FREE_SPACE_H_
